Christophe Bernard

Questions and Answers (8) View all

• Answer added in Patch Clamp Recording
  14 What is the best slicing direction for low-magnesium seizure-like experiments on mouse brain?
  By Ehsan Negahbani · The University of Waikato
  Christophe Bernard · Aix-Marseille Université

  In adult slices, the best procedure is to perfuse animals with ice cold modified ACSF. There are many different ways. Since performing dendritic reco... [more]

  In adult slices, the best procedure is to perfuse animals with ice cold modified ACSF. There are many different ways. Since performing dendritic recordings critically depends on slice quality, you can check the method in http://www.nature.com/nprot/journal/v1/n3/full/nprot.2006.164.html if you want good activity, it is better to use the dual flow chamber: http://www.ncbi.nlm.nih.gov/pubmed/19200237 hope that helps
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• Answer added in Patch Clamp Recording
  14 What is the best slicing direction for low-magnesium seizure-like experiments on mouse brain?
  By Ehsan Negahbani · The University of Waikato
  Christophe Bernard · Aix-Marseille Université

  There are many factors that can influence the production of SLEs Age is critical: the older the animal the more difficult it is Slice thickness, the t... [more]

  There are many factors that can influence the production of SLEs Age is critical: the older the animal the more difficult it is Slice thickness, the thicker the better (you need the max of connectivity), with mice you can go up to 500-600 um in adult Perfusion speed, the faster the better, up to 8-10 ml/min Temperature, must be physiological, around 35 (can be tricky to maintain at high perfusion speed without degassing) Slice orientation. If you cur sagittal, use slices from dorsal hippocampus (parasagittal may work, but I have not checked). Increasing K, and bicu may work, but I have experienced that too epilepetogenic conditions kill epilepsy If you want to benchmark your preparation, just use 0 Ca ACSF, which invariably triggers SLEs (check J. Jefferys' papers). That way you are sure that everything works (slice orientation, hippo-Cx propagation etc).
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• Answer added in Patch Clamp Recording
  12 Compared to hippocampal slices from rat, how common/easy is it to prepare such slices from mouse brain?
  By Ehsan Negahbani · The University of Waikato
  Christophe Bernard · Aix-Marseille Université

  Before answering your questions, it would be more important to know what your project is. For example, if you want to study seizure propagation, you c... [more]

  Before answering your questions, it would be more important to know what your project is. For example, if you want to study seizure propagation, you can use thalamo-cortical slices (e.g. papers from J. Huguenard's group). Hence, it all depends upon your own question. Regarding the in toto. I designed this prep a long time ago 1997. I tested it also with the whole cortex, and it works. The trick is to dissect out the cortex without damaging it. Not so tough. Many people have used the prep, mostly with the hippocampus: papers from the groups of K. Staley (Boston); Y. Ben-Ari (Marseilles, France) and S. Williams (Canada).
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• Answer added in Synaptic Plasticity
  4 Concerning in vivo electrophysiology, what are the most reliable criteria to exclude animals from an experimental population?
  By José Cruz · University of Coimbra
  Christophe Bernard · Aix-Marseille Université

  Hi José, This failure to induce LTP is part of the physiological response. It is not an outlier. It may depend upon the angle for the slice, how old ... [more]

  Hi José, This failure to induce LTP is part of the physiological response. It is not an outlier. It may depend upon the angle for the slice, how old the slice is etc. Hence, it is NORMAL to have LTP failure. We have it everyday, more for mice than for rat for some reason. What we do is be honnest; i.e. LTP failed in XX slice out of YY from ZZ animals. Then, if you compare two conditions, you can not only compare the amount of LTP but also the failure rate, which is also a very good indication about modifications.
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• Answer added in Patch Clamp Recording
  12 Compared to hippocampal slices from rat, how common/easy is it to prepare such slices from mouse brain?
  By Ehsan Negahbani · The University of Waikato
  Christophe Bernard · Aix-Marseille Université

  There is no difference between mice and rats in terms of viability. The main difference, is that you get more connected neurones in a 400 um slice fro... [more]

  There is no difference between mice and rats in terms of viability. The main difference, is that you get more connected neurones in a 400 um slice from a mice (this is the size issue). Depending upon the age of the animals you use, you could use the in toto preparation, which works nicely till postnatal day 14. We use it all the time with low Mg experiments, e.g. Quilichini et al, Neuron, 2012
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